Vibrations inside turbine at Muskrat Falls hydroelectric dam raise concerns

The construction site of the hydroelectric facility at Muskrat Falls, Newfoundland and Labrador. (THE CANADIAN PRESS/Andrew Vaughan)

The Crown corporation that generates most of the electricity in Newfoundland and Labrador says one of the four turbines at the Muskrat Falls hydroelectric dam will likely be taken apart and repaired because of vibrations first detected in 2021.

Jennifer Williams, CEO of Newfoundland and Labrador Hydro, said Wednesday the work needed on Unit 2 won't affect the utility's supply of electricity to customers inside or outside the province. As well, Williams said the material costs will be covered by insurance.

"We've been investigating with the manufacturer to determine what the right, long-term solution is for this unit," Williams said in an interview. "The unit itself has been in service. It ... hasn't been underperforming by any stretch ... It hasn't been vibrating in the zone that we keep it in."

As well, she said the other turbines have not been experiencing similar vibrations.

Williams was responding to findings in a consultant's quarterly report that suggested the Crown corporation should consider the potential challenges presented by the "longer-term accelerated degradation" of all four units.

The CEO said the reports from Liberty Consulting are intended to provide a "cautionary" approach to potential risks.

Williams said the issues outlined in the report amount to the usual "teething" problems experienced by relatively new hydroelectric projects, noting that the Muskrat Falls project was commissioned in April.

"You plan for and expect that there's going to be bumps and bruises," she said. "So there's been a long-standing commitment to make sure that we have other assets planned to be in service while we experience early in-service issues."

Planning for the repair job has yet to be completed, which means a cost estimate would be premature at this stage, she said.

"We're in the final stages of finalizing what this option looks like."

As of June 29, the cost of the Muskrat Falls project had reached $13.5 billion. When the province sanctioned the project in 2012, the full cost was estimated at $7.4 billion.

"It was a big project and any big project doesn't get executed exactly as it is on paper," Williams said. "I'm not minimizing the concerns that customers have, but we do have to be thoughtful about how any large project is going to unfold."

This report by The Canadian Press was first published July 12, 2023.